Purpose:

Limited evidence shows that switching anti-TNF therapy in ankylosing spondylitis may be effective. However, there are no data on the switch from infliximab (IFX) to adalimumab (ADA). In Crohn's patients, ADA therapy in patients resistant or intolerant to IFX has been studied by several authors. Aim of the study was to assess the clinical response to the treatment with ADA in Crohn's-related spondylarthritis in patient resistant or intolerant to IFX.

Methods:

ADA was administered 40 mg sc eow in patients diagnosed with Crohn's disease and spondylarthritis, who had stopped the treatment with IFX due to intolerance or non-responsiveness, starting at least after 8 weeks from the last injection of IFX. Concurrent therapies were continued during the study, and dose adjustments allowed. Patients were followed-up to one year, and clinic visits were performed at baseline, and after 4, 12, 24, and 52 weeks of treatment with ADA. At each visit spondylitis activity and function were assessed by the BASDAI, and the BASFI scores. The response to treatment was evaluated by the ASAS20 score. Crohn's disease activity was assessed by the CDAI score, and quality of life by the SF-36 questionnaire. The variation of clinical measures was evaluated by Wilcoxon test, and differences in proportions by chi-square test.

Results:

18 patients entered the study (12 F 6 M, mean age 43.55 ± 13.1 yrs). Mean duration of IFX treatment was 92.09 (range 2  256) weeks. Reason for IFX discontinuation were inefficacy (N=12) or intolerance (N=6). Crohn's disease activity was low in all patients (CDAI < 150). 13 patient had active spondylitis, (BASDAI score > 4). 15 patients completed the week 24 visit, and 12 the week 52 visit. ADA was discontinued in 3 patients, due to Crohn's related complications or articular flare-up (N=1). The variation of BASDAI and BASFI clinical scores are reported in Figures 1 and 2. During the study, both the BASDAI and the BASFI improved as compared to study entry levels, significant differences vs baseline values being recorded only up to the 6th month for BASDAI, and up to the 3rd month for BASFI. BASDAI reduction > 50% and ASAS20 responses were recorded in 3/18, 7/18, 3/15, and 2/15 patients, and in 3/18, 4/18, 3/18, and 2/18 patients at month 1, 3, 6, and 12 respectively. Only patients with BASDAI > 4 at entry showed ASAS20 responses. However, the proportion of responders was not statistically significant by chi-square test. CDAI and SF-36 scores changed little during the study. Overall, the effect of treatment on all considered variables, reached a maximum at the 3rd month, but was not maintained at subsequent assessments, being minimal at the 12th month.

Fig. 1. Mean BASDAI variation during treatment with Adalimumab.

Fig. 2. Mean BASFI variation during treatment with Adalimumab.

Conclusion:

Our study is, to our knowledge, the first addressing the effectiveness of adalimumab in Crohn's-related spondylarthritis after failure of infliximab. Our results suggest that treatment with ADA may be a suitable option in these patients. However, the magnitude and duration of therapeutic effect should be further investigated.